The present invention is directed to a strainer designed to protect high, intermediate, and low pressure turbines from debris. Strainers are an important component in valves, traps and similar equipment. A pipe line strainer is a device which, when installed in a pipe line, provides a means of mechanically removing solids from a flowing fluid or gas by utilizing a perforated or mesh straining element. Strainers are generally employed in pipelines to protect mechanical equipment such as condensers, heat exchangers, meters, spray nozzles and turbines from the detrimental effects of sediment, rust, pipe scale or other extraneous debris.
There have been numerous types of prior art steam strainers. Two of the more common types of these devices are the Y-type strainer and bucket strainer. Prior art strainers have typically experienced several problems. First, they frequently do not provide smooth flow characteristics and often leak. Secondly, prior art strainers typically incorporate thin screens which can become distorted over time due to the flow of debris. Finally, prior art strainers can be difficult to remove or adjust.
The present invention is directed to an improved strainer for preventing debris from entering a turbine. The strainer of the present invention exhibits improved flow characteristics, does not buckle under pressure, and does not produce a significant reduction or loss in operating pressure.
It is an object of the present invention to provide a strainer which provides smooth flow characteristics.
It is still a further object of the present invention to provide a strainer which includes a labyrinth seal to provide a tight seal and to prevent leakage.
It is still a further object of the present invention to provide a strainer in which a bonnet cage supports the screen.
It is an additional object of the present invention to provide a pressure strainer in which circumferential grooves around the bonnet cage increase the total free flow area and thereby reduce pressure loss.